Hi everyone,
I found a link here from the citrus board on Gardenweb.

I've become obsessed, absolutely in LUUUUUVE, with citrus in the last month or so. I've gone crazy buying a couple satsumas, a meyer, a navel, and I'm planning to order a couple more varieties.

I want to plant most of them on a patio in terra cotta pots that live outside year round. I'm in the East Bay of Northern Cal... zone 9.

Anyway, I have done all my reading about potting mix and i'm gung ho to try the light, free-draining mix that's so popular there at GW, "Al's mix" of wood bark/perlite/peat.

But I'm very curious about the fertilizing issue... since a lot of people there claim that you really can't do organic with containers... and growing organic is something that's really important to me.

Any tips for organic fertilizers or really good products? I bought the EB Stone citrus blend, but am wondering if I'm still going to have to use something else monthly? Fish emulsion maybe?

Any advice you want to share for this total newbie is much appreciated.

Thanks,
Kristi

Kristi, you can grow citrus using organic fertilizers. However, know that citrus are big feeders, and require a lot of nutrients. Two major ingredients in particular required by citrus trees are, - nitrogen and potassium. The major difficulty that organic fertilizing presents is supplying enough potassium. A citrus tree, in fact any plant, can only utilize a fertilizer element when that element is in the water soluble form. With organics supplying soluble potassium is extremely limited, therefore the tree's production becomes limited. Lastly, organic grown citrus trees, always, again I say always, produce smaller crops. Anyway, welcome to the Citrus Growers forum. We are excited that you have joined. Take care. - Millet

I don't really want to bust your bubble about organic gardening, but plants take up nutrients in only a few "chemical" forms, like NH4+, or NO3-. They do not take up "organic" forms such as proteins. If you use the term organic in a chemical sense, urea is an organic chemical and is taken up by citrus. "Organic" fertilizers in the sense you are talking about must be broken down to the same "chemical" forms that are found in commercial fertilizers--it makes no difference to the plant if the NH4+ or NO3- came from the breakdown of a protein or from a pellet of commerial fertilizer.

Organic gardening has much more relevance in gardening where the addition of organic material improves the nature of the soil. With citrus in containers, you already have a very organic soil mix---pine bark and peat moss. The remaining thing that citrus plants need is N, P and K plus trace minerals and they need it in higher quantities than can be supplied by the breakdown of "organic" fertilizers.

For the most part, I only use synthetic fertilizers unless an organic is on clearance. However, one complaint that I've heard about synthetic is that they they have a high salt content. Does anyone know if that's true or is it a wives' tale? Also when they say salt, is it in the form of NaCl that they are talking about? There's plenty of other salts out there and I'm wondering if there's just a confusion about the good salts and bad salts.

Phillip

Hey guys, thanks for the responses.

Millet and Skeeter, so are you saying EB Stone's Citrus food WON'T work?

And if I still need a source of potassium, what provides that?

Do you know of a good primer or link somewhere with a good "Fertilizing 101" type info for beginners?

Phillip is right--the trees don't care where the nutrients come from, whether it starts as an organic form of N or as an inorganic form--it pretty much has to turn into the "chemical" form to become available to the plant. As Millet said it is a matter of supply-- water soluble fertilizers like Miracle Grow that you add to water are instantly available to the plant, but the problem with them is that they wash right out of containers, so you have to use they with almost every watering. Granular fertilizers are not much better at staying around, most of the nutrients are dissolved and washed into the soil after just a few waterings. So slow release pellets are the best for container citrus, providing a steady supply at a fairly high rate for about 3-4 months in the growing season. Organic fertilizers do supply their nutrients over a longer period since they require degredation to become available to the plant, however that breakdown does not provide a steady supply over time --especially for all of the nutrients and as Millet said it may not deliver enough K through much of the time.

As for your question Phillip, "salt" in the sense of buildup in the soil is not actually NaCl, but a mixture of inorganic ions that combine as the various components are used. All water soluble inorganic compounds are made up of anions and cations--together they make a soluble salt, but not all salts are highly soluble. When a fertilizer is added as say ammonium phosphate, and the ammonium ion gets removed by the plant, the charge balance for the phosphate left in the water (soil) must be met by some other cation (like H+ or Na+). Some of these are not highly soluble and can build-up in the soil and require flushing to remove them.

I should add one point about organic fertilizers that relates to Phillip's question about salts--that is one of the good things about organic N fertilizers (there is actually no such thing as an organic form of potassium--it is always an ion and therefore inorganic). Organic N does not create a salt residue. There are several "chemical" forms of N that also do not create salt-- urea, ammonium nitrate and annhydrous ammonia (not available for home users).

To make it simple. Nitrogen is nitrogen is nitrogen is nitrogen. Nitrogen from a chemical fertilizer is EXACTLY THE SAME as nitrogen from ANY source of organic fertilizer. Many organic growers use manure a very common organic fertilizer, but manure is EXTREMELY high in soluble salts, therefore manure is not suitable for pots and containers. One major sources of soluble salts comes from the water used. - Millet

Very true Millet-- I did not think about the salts in manure and in water.

When it comes to gardening, I am sort of a hybrid--I believe in the benefits of adding organic matter to the soil to change it's physical properties--the nutrients that are supplied by that are just a bonus. I use commercial fertilizers to supply the majority of nutrients. I also try to avoid using pesticides, but there are times when they are necessary and I try to use those that are least persistient but effective--mainly synthetic pyrethroids and IGRs (insect growth regulators).

I too am a hybrid when it comes to chemical verses organic. Our farm uses herbicides, insecticides and chemical fertilizers. We also plant rye as a green manure crop which we turn under to add organic matter to the soil. To get an idea of the extent of Rye's well developed fibrous root system, the roots of one adult rye plant was once counted and measured. It bore approximately 14 million root segments totaling an unbelievable 280 miles (630 kilometers) in length. Rye is an excellent green manure crop to in rich the soil. - Millet

Hey Guys,
I'm still trying to absorb everything I have read here and haven't had a chance to post back a big "Thank You" for answering my questions.

I've been reading what I can about growing containers organically... and I have one thing that's still in the back of my mind.

I think Skeeter wrote:
"the trees don't care where the nutrients come from, whether it starts as an organic form of N or as an inorganic form--it pretty much has to turn into the "chemical" form to become available to the plant"

Problem is, _I_ care where the nutrient comes from. I'm reluctant to use a bunch of petro-chemicals on my food products because I'm afraid of the chemical residues in and on the food.

So what I'm wondering is... if I were to use something like a Miracle Grow or other "chemical" fertilizer or osmocote... do those chemicals stay behind in or on the fruit? On the fruit, I suppose I can handle. IN the fruit would be a deal breaker for me.


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I've also seen a bunch of places on GardenWeb where people say they have been able to grow citrus in containers using the fish-emulsions/sea kelps, but here you guys tend to say it really reduces the yield.

If I were to use the liquid organics, are there any out there that are really the best? Or is there some sort of "semi-organic/natural" products that can yeild a respectable amount?

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Finally, I hear a lot about container temperature and nutrient uptake. Can someone boil it down to the pertinent points or lead me to a post or FAQ about this? My general understanding is that the hotter or colder the pot the slower the microbe activity needed for processing the organic fertilizers? But is there a magic range of temps? I am somewhat lucky I live in Northern California in a fairly temperate climate... yet we had a few days of 80-90 weather last week that threw us all for a loop.


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THANKS again!

I have always thought that "Chemical" fertilizers are a cleaner and safer type of chemical to use than are "organic" chemicals. I would much rather have nitrogen from a bag on my tree than some animal's waste (manure & urine). But each to their own. In the final analysis, yes citrus can be grown organically, but as has been said, what the roots take up into the tree and into the fruit, is exactly the same nutrients - no difference- (chemicals) no matter which method your use. The "residues" in the tree and fruit that you are concerned about will be exactly -no difference- the same residues no matter which method of fertilization you use. About the temperature question you asked. For optimum growth keep your tree between 76-86F. At temperatures below 55F or above 95F the trees growth stops. I strive for 86F. Take care, and happy and successful growing by what ever method you decide. - Millet